What Is a Low Percentage of Ash in Cat Food?

by Elle Di Jensen

Low ash content alone doesn't always solve UTI problems.

If your kitty has experienced a urinary tract infection (UTI) or two, the vet probably has told you to switch him to a cat food with a low percentage of ash. Any food you feed him has ash, so your job is to determine how low is "low."

Less Than 10 Percent

Recognizing that cat parents are increasingly becoming label readers, many cat food manufacturers produce cat food advertized with a low ash content. When you compare those labels, look for a kibble that has no more than eight percent ash listed under the nutritional information.

What About Canned Food?

You might expect dry kibble to contain ash, but you may be surprised to learn that canned food contains it, as well. That means that even if your cat's diet is exclusively or mostly canned food, it's just as important to read labels. If the vet wants your cat on a low ash food, look for canned food that has no more than 3 percent ash content.

What Is Ash?

Maybe you question why there is any level of ash in your kitty's food. It's not just an unfortunate manufacturing by-product. When you see "ash" listed on a cat food label, it actually refers to the amount of mineral elements that are left after a sample of the food is put through a two-hour burn in a laboratory. These are essential minerals, like calcium, manganese, magnesium, phosphorus, potassium and sodium. So, the presence of ash in your cat's food actually can be a good thing.

Low Ash Versus Low Magnesium

Don't rely solely on low ash in a food to be good for your kitty if he's prone to UTI's. High ash in general is thought to be the problem for those sensitive felines, but it actually is the high magnesium content a high ash food has that causes crystals to form in cats' urinary tracts. Look for low ash content, but low magnesium content as well. You want to serve your fluffy friend kitty food that has less than 0.12 percent magnesium to keep those crystals from developing.

About the Author

Elle Di Jensen has been a writer and editor since 1990. She began working in the fitness industry in 1987, and her experience includes editing and publishing a workout manual. She has an extended family of pets, including special needs animals. Jensen attended Idaho and Boise State Universities. Her work has appeared in various print and online publications.